"New discoveries of many super-Earth planets orbiting very close to sun-like stars have started to
make Earth’s solar system look a little lonely. The mystery of why Earth ended up without any super-Earth cousins continues to puzzle astronomers as they try to better understand the unusual history of the solar system and the evolution of planets in general. The uniqueness of our solar system first became clear when astronomers began discovering hundreds of extrasolar planets orbiting other stars. They recently found that around 30 to 50 percent of stars similar to the Sun have hot super-Earths—planets orbiting very close to their parent stars with up to 10 times as much mass as Earth.
“The Solar System is just one possible outcome of planet formation and it might be an unusual case,” said Sean Raymond, an astronomer at the Laboratoire d’Astrophysique de Bordeaux.... One big unknown is how hot super-Earths form in the first place, a mystery that has spawned at least two competing theories among astronomers.
Some astronomers favor an 1) “in-situ formation” model, which suggests hot super-Earths grew very fast near their parent stars because they had enough mass from huge disks of rocky debris. But Raymond doesn’t buy this idea for several reasons.
First, Raymond notes that the scenario requires a very large amount of mass close to the star —something that conflicts with observations about dusty debris disks surrounding other stars, and the current understanding of disk physics.
Second, many studies have shown that Earth-sized planets within such disks tend to migrate toward their parent stars from farther out rather than stay still.
Instead, Raymond favors the 2) “inward migration” model that suggests super-Earths first formed farther out from their parent stars. That means the planets originally formed in a colder region beyond the so-called “frost line,” the point where water and other chemical compounds that contain hydrogen will condense into solid ice. By comparison, Earth probably formed inside the frost line and later received its water in the form of asteroids or other debris from beyond the frost line."
Astrobiology
3) Through faith we understand that the worlds were framed by the word of God,
Hebrews 11:3
“The Solar System is just one possible outcome of planet formation and it might be an unusual case,” said Sean Raymond, an astronomer at the Laboratoire d’Astrophysique de Bordeaux.... One big unknown is how hot super-Earths form in the first place, a mystery that has spawned at least two competing theories among astronomers.
Some astronomers favor an 1) “in-situ formation” model, which suggests hot super-Earths grew very fast near their parent stars because they had enough mass from huge disks of rocky debris. But Raymond doesn’t buy this idea for several reasons.
First, Raymond notes that the scenario requires a very large amount of mass close to the star —something that conflicts with observations about dusty debris disks surrounding other stars, and the current understanding of disk physics.
Second, many studies have shown that Earth-sized planets within such disks tend to migrate toward their parent stars from farther out rather than stay still.
Instead, Raymond favors the 2) “inward migration” model that suggests super-Earths first formed farther out from their parent stars. That means the planets originally formed in a colder region beyond the so-called “frost line,” the point where water and other chemical compounds that contain hydrogen will condense into solid ice. By comparison, Earth probably formed inside the frost line and later received its water in the form of asteroids or other debris from beyond the frost line."
Astrobiology
3) Through faith we understand that the worlds were framed by the word of God,
Hebrews 11:3
